With recent achievement of multifunctional purposes such as for electronic devices, communication devices and automobiles, electrochemical elements such as lithium ion batteries, lead batteries and capacitors require further improvements of properties, such as higher output or higher capacity and improvements of mechanical properties. In such a situation, improvements in performance of electrodes for electrochemical elements have been attempted in order to improve performance of electrochemical elements.
An electrode for electrochemical elements is formed, for example, by forming, into a sheet, an electrode material containing an electrode active material and the like, followed by press-bonding the sheet (electrode composition layer) as a coating material onto a collector. JP-A-2013-77560 describes a method in which composite particle powder including an active material, a conductive material and a binder is supplied as a coating material to a space between a pair of rolls that rotate in the opposite direction to each other, is compressed to attach the coating material onto the surface of one of the rolls, and the coating material is transferred onto a collector, thereby producing an electrode for electrochemical elements.
However, in the technique described in JP-A-2013-77560, as shown in FIG. 5, in order to completely transfer a mixture coating material 33, which is a coating material, from a first roll 31 onto a second roll 32, the mixture coating material 33 is supplied continuously and directly onto the surface of the first roll 31 in a roll gap 34. Consequently, the surface of the first roll 31 is easily abraded due to friction between the surface of the first roll 31 and the mixture coating material 33.
When the surface of the first roll 31 is abraded, residual extraneous materials are generated from the surface of the first roll 31. At a time of production of an electrochemical element or an electrochemical reaction, a short-circuit is easily caused between a cathode and an anode due to such residual extraneous materials, causing defectiveness. Therefore, there are problems that this results in deteriorations in the quality of the electrode for electrochemical elements and that the production efficiency will also be deteriorated.